The most reliable way to find your bra size at home is to measure around your ribcage for band size, then check whether you are spilling out of or gapping in your current cup. The number on the tag rarely matches what actually fits, and once you know both measurements, remember that the band does most of the work. It is 80% of the fit of the bra.
Measuring your band size
Wrap a tape measure around your ribcage, right under your bust, keeping it horizontal to the ground. Pull it snug, but not so tight that it cuts into your skin. Match your measurement to the chart below to find your band size.
| Your measurement | 27-29" | 29-32" | 33-34" | 35-39" | 39-41" | 42-43" | 44-45" | 46-47" | 48-49" |
|---|---|---|---|---|---|---|---|---|---|
| Band size | 32 | 34 | 36 | 38 | 40 | 42 | 44 | 46 | 48 |
If the band feels too tight once you are wearing it, go up in cup size before you reach for a bigger band. The band should stay snug on its loosest hook when it is new, since the elastic relaxes with wear over time, giving you room to tighten it later.
Getting your cup size right
Once your band fits, look at the cup. Are you spilling out of the top or sides? Go up a cup size. Is there a gap, with the fabric not quite touching your skin? Go down a cup size. It is genuinely that simple, and it is normal to try a couple of sizes before landing on the right one, especially the first time you are doing this at home instead of in a fitting room.
More ways to check the fit
Band and cup size get you most of the way there, but a few more checks confirm you actually have it right:
- The center of the bra should lie flat against your chest, without a gap.
- Try lifting your arms up and down. A bra that fits stays in place.
- Your band should stay level all the way around your back. If it rides up, it is either too big or needs tightening.
- The underwire, if you wear one, should lie flat against your ribcage.
- There should not be any spilling out of the top, sides, or bottom of the cup.
- If the cups are wrinkling or puckering, go down a cup size.
- A new bra should fit comfortably on the first hook, giving you room to tighten as it wears in.
A note on US, UK, and European sizing
We carry brands sized in the US, the UK, and Europe, and the letters do not always mean the same thing across systems. A UK D cup, for example, sits in a different place than a US D cup once you compare actual cup volume. Every brand also fits a little differently even within the same sizing system, so a size that fits in one brand may run larger or smaller in another. We have put together a full international size conversion guide if you are comparing a specific brand.
When a fitting beats a tape measure
A tape measure gets you close, but it cannot tell you how a specific bra's cut, wire, or fabric will sit on your particular shape. That is where a professional fitting makes the real difference. It is $25, waived with a bra purchase, no appointment needed, and it accounts for everything a chart cannot: how your body has changed, how a brand actually fits, and which style will look and feel right on you specifically.
Still not sure?
Full details, including our dress size and body measurement charts, live on our sizing guide page. Or skip the guesswork and come in for a fitting. Your Bra Sisters do this every day and can usually tell your size within a minute or two of watching you try on a couple of styles.